1. Field of the Invention
The present invention relates to a sample separating apparatus and method, and a substrate manufacturing method and, for example, to an apparatus and method of separating a plate-like sample having an internal fragile layer at the fragile layer, a sample support apparatus used in the separating apparatus, and a substrate manufacturing method using the separating apparatus.
2. Description of the Related Art
A substrate (SOI substrate) having an SOI (Silicon On Insulator) structure is known as a substrate having a single-crystal Si layer on an insulating layer. A device using this SOI substrate has many advantages that cannot be achieved by ordinary Si substrates. Examples of the advantages are as follows.
(1) The integration degree can be increased because dielectric isolation is easy.
(2) The radiation resistance can be increased.
(3) The operating speed of the device can be increased because the stray capacitance is small.
(4) No well step is necessary.
(5) Latch-up can be prevented.
(6) A completely depleted field-effect transistor can be formed by thin film formation.
Since an SOI structure has the above various advantages, researches have been made on its formation method for several decades.
As one SOI technology, an SOS (Silicon On Sapphire) technology by which Si is heteroepitaxially grown on a single-crystal sapphire substrate by CVD (Chemical Vapor Deposition) has been known for a long time. This SOS technology was once recognized as the most matured SOI technology. However, the SOS technology has not been put into practical use to date because, e.g., a large amount of crystal defects are produced by lattice mismatch in the interface between the Si layer and the underlying sapphire substrate, aluminum that forms the sapphire substrate mixes in the Si layer, the substrate is expensive, and it is difficult to obtain a large area.
Various SOI technology appeared following the SOS technology. For these SOI technologies, various methods have been examined aiming at reducing crystal defects or manufacturing cost. There are a method of implanting oxygen ions into a substrate to form a buried oxide layer, a method of bonding two wafers via an oxide film and polishing or etching one of the wafers to leave a thin single-crystal Si layer on the oxide film, and a method of implanting hydrogen ions to a predetermined depth from the surface of an Si substrate having an oxide film, bonding the Si substrate to the other substrate, and peeling the latter substrate (the other substrate) by a heat treatment while leaving a thin single-crystal Si layer on the oxide film.
The present applicant has disclosed a new SOI technology in Japanese Patent Laid-Open No. 5-21338. In this technology, a first substrate obtained by forming a non-porous single-crystal layer (including a single-crystal Si layer) on a single-crystal semiconductor substrate having a porous layer is bonded to a second substrate via an insulating layer (SiO2), and the two substrates are separated from the porous layer to transfer the non-porous single-crystal layer to the second substrate. This technology is advantageous in that the SOI layer has high film thickness uniformity, the crystal defect density in the SOI layer can be decreased, the SOI layer has high surface planarity, no expensive special fabrication apparatus is necessary, and SOI substrates having SOI films about a few hundred xcx9c to 10 xcexcm thick can be fabricated by the same fabrication apparatus.
In addition, the present applicant has disclosed another technology in Japanese Patent Laid-Open No. 7-302889 in which, after the first and second substrates described above are bonded, the first substrate is separated from the second substrate without breaking, and the separated first substrate is reused by smoothening the surface and again forming a porous layer. Since the first substrate can be economically used, this technology has the advantages that the fabrication cost can be largely reduced and the fabrication process is also simple.
In the above technologies, however, when the two bonded substrates are separated it is necessary to prevent damages to the substrates and protect the fabrication apparatus and the like from contamination caused by the generation of particles.
The present invention has been made in consideration of the above situation, and has as its object to provide a separating apparatus and method suitable to separate a sample such as a substrate, a sample support apparatus used in this separating apparatus, and a substrate manufacturing method using the separating apparatus.
According to the present invention, there is provided a separating apparatus for separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising a jet unit for ejecting a fluid to the sample, and a pair of holding portions opposing each other to sandwich and hold the sample, wherein the pair of holding portions hold the sample to allow the sample to expand at a vicinity of a central portion due to a pressure of the fluid ejected from the jet unit and injected into the sample.
According to the present invention, there is also provided a separating apparatus for separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising a jet unit for ejecting a fluid to the sample, and a pair of holding portions opposing each other to sandwich and hold the sample, wherein the pair of holding portions hold the sample which can corrugate due to a pressure of the fluid ejected from the jet unit and injected into the sample.
In the separating apparatus, preferably, at least one of the pair of holding portions has a hollow contact portion, and the sample is held by bringing the contact portion into contact with the sample. The contact portion may comprise a multiple of contact portions.
In the separating apparatus, preferably, at least one of the pair of holding portions has an annular contact portion, and the sample is held by bringing the contact portion into contact with the sample. The contact portion may comprise a multiple of contact portions.
In the separating apparatus, preferably, at least one of the pair of holding portions has one or a plurality of stripe-shaped contact portions, and the sample is held by bringing the contact portion into contact with the sample.
In the separating apparatus, preferably, at least one of the pair of holding portions has one or a plurality of arcuated contact portions, and the sample is held by bringing the contact portion into contact with the sample.
In the separating apparatus, preferably, at least one of the pair of holding portions has one or a plurality of projecting contact portions on a main body surface, and the sample is held by bringing the contact portion into contact with the sample.
In the separating apparatus, preferably, at least one of the pair of holding portions has a radial contact portion, and the sample is held by bringing the contact portion into contact with the sample.
In the separating apparatus, preferably, at least one of the pair of holding portions has a contact portion which comes into contact with a peripheral portion of the sample, and the sample is held by bringing the contact portion into contact with the sample. Preferably, the contact portion can contact the whole peripheral portion of the sample.
The separating apparatus preferably further comprises a rotary mechanism for rotating the holding portion about a shaft perpendicular to a surface of the sample.
The separating apparatus preferably further comprises an adjustment mechanism for adjusting an interval between the pair of holding portions.
In the separating apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism presses the sample to adjust the interval between the pair of holding portions.
In the separating apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism maintains a substantially constant interval between the pair of holding portions.
In the separating apparatus, preferably, each of the pair of holding portions has a chuck mechanism for vacuum-chucking the sample.
The separating apparatus is suitable for processing of separating a substrate having a porous layer as the fragile layer.
According to the present invention, there is also provided a support apparatus for supporting a sample, which is used in a separating apparatus for separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising a pair of holding portions opposing each other to sandwich and hold the sample, wherein the pair of holding portions hold the sample to allow the sample to expand at a vicinity of a central portion due to a pressure of a fluid ejected from a jet unit arranged in the separating apparatus and injected into the sample.
According to the present invention, there is also provided a support apparatus for supporting a sample, which is used in a separating apparatus for separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising a pair of holding portions opposing each other to sandwich and hold the sample, wherein the pair of holding portions hold the sample to allow the sample to corrugate due to a pressure of a fluid ejected from a jet unit arranged in the separating apparatus and injected into the sample.
In the support apparatus, preferably, at least one of the pair of holding portions has a hollow contact portion, and the sample is held by bringing the contact portion into contact with the sample. The contact portion may comprise a multiple of contact portions.
In the support apparatus, preferably, at least one of the pair of holding portions has an annular contact portion, and the sample is held by bringing the contact portion into contact with the sample. The contact portion may comprise a multiple of contact portions.
In the support apparatus, preferably, at least one of the pair of holding portions has one or a plurality of stripe-shaped contact portions, and the sample is held by bringing the contact portion into contact with the sample.
In the support apparatus, preferably, at least one of the pair of holding portions has one or a plurality of arcuated contact portions, and the sample is held by bringing the contact portion into contact with the sample.
In the support apparatus, preferably, at least one of the pair of holding portions has one or a plurality of projecting contact portions on a main body surface, and the sample is held by bringing the contact portion into contact with the sample.
In the support apparatus, preferably, at least one of the pair of holding portions has a radial contact portion, and the sample is held by bringing the contact portion into contact with the sample.
In the support apparatus, preferably, at least one of the pair of holding portions has a contact portion which comes into contact with a peripheral portion of the sample, and the sample is held by bringing the contact portion into contact with the sample. Preferably, the contact portion can contact the whole peripheral portion of the sample.
The support apparatus preferably further comprises a rotary mechanism for rotating the holding portion about a shaft perpendicular to a surface of the sample.
The support apparatus preferably further comprises an adjustment mechanism for adjusting an interval between the pair of holding portions.
In the support apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism presses the sample to adjust the interval between the pair of holding portions.
In the support apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism maintains a substantially constant interval between the pair of holding portions.
In the support apparatus, preferably, each of the pair of holding portions has a chuck mechanism for vacuum-chucking the sample.
The support apparatus is suitable as a support apparatus for supporting a substrate having a porous layer as the fragile layer during separation processing.
According to the present invention, there is also provided a sample separating method characterized by comprising separating a sample having a fragile layer using the above separating apparatus.
In the separating method, preferably, water is used as the fluid to be ejected from the jet unit.
According to the present invention, there is also provided a separating method of separating a substrate at a porous layer, the substrate being formed by bonding a non-porous layer side of a first substrate, in which the porous layer and the non-porous layer are sequentially formed on one surface, to a second substrate, characterized in that the above separating apparatus is used for separation.
According to the present invention, there is also provided a substrate manufacturing method characterized by comprising the step of bonding a non-porous layer side of a first substrate, in which a porous layer and the non-porous layer are sequentially formed on one surface, to a second substrate, and separating the bonded substrates at the porous layer, wherein the above separating apparatus is used in the separation step.
According to the present invention, there is also provided a separating apparatus for separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising a jet unit for ejecting a fluid to the sample, and a pair of holding portions opposing each other to sandwich and hold the sample, wherein the pair of holding portions allow the sample to warp as the sample is divided into two parts by a pressure of the fluid ejected from the jet unit and injected into the sample and simultaneously limit a warp amount.
In the separating apparatus, preferably, at least one of the pair of holding portions has a smooth convex support surface, and the sample is held by the support surface.
In the separating apparatus, the support surface preferably substantially comprises part of a spherical surface.
In the separating apparatus, the support surface preferably comprises a surface formed by a cone with a convex vertex.
In the separating apparatus, the support surface preferably substantially comprises a surface formed by a frustum of a cone.
In the separating apparatus, the support surface preferably comprises a smooth convex surface formed by a stack of several frustums.
In the separating apparatus, the support surface preferably comprises a convex surface formed by a stack of several columns.
In the separating apparatus, at least one of the pair of holding portions preferably includes an elastic member and deforms due to a force inflicted by the sample.
In the separating apparatus, preferably, at least one of the holding portions has a support portion partially consisting of an elastic material, and the sample is held by the support portion.
In the separating apparatus, at least one of the holding portions preferably has an elastic member at a portion which can contact the sample.
In the separating apparatus, at least one of the holding portions preferably has an annular support portion consisting of an elastic member.
In the separating apparatus, at least one of the holding portions preferably has a support portion coupled to a main body via an elastic member.
The separating apparatus preferably further comprises a rotary mechanism for rotating the holding portion about a shaft perpendicular to a surface of the sample.
The separating apparatus preferably further comprises an adjustment mechanism for adjusting an interval between the pair of holding portions.
In the separating apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism presses the sample to adjust the interval between the pair of holding portions.
In the separating apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism maintains a substantially constant interval between the pair of holding portions.
In the separating apparatus, each of the pair of holding portions preferably has a chuck mechanism for vacuum-chucking the sample.
The separating apparatus is suitable for processing of separating a substrate having a porous layer as the fragile layer.
According to the present invention, there is also provided a support apparatus for supporting a sample, which is used in a separating apparatus for separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising a pair of holding portions for sandwiching and holding the sample, wherein the pair of holding portions allow the sample to warp as the sample is divided into two parts by a pressure of the fluid ejected from a jet unit arranged in the separating apparatus and injected into the sample and simultaneously limit a warp amount.
In the support apparatus, preferably, at least one of the pair of holding portions has a smooth convex support surface, and the sample is held by the support surface.
In the support apparatus, the support surface preferably substantially comprises part of a spherical surface.
In the support apparatus, the support surface preferably comprises a surface formed by a cone with a convex vertex.
In the support apparatus, the support surface preferably substantially comprises a surface formed by a frustum of a cone.
In the support apparatus, the support surface preferably comprises a smooth convex surface formed by a stack of several frustums.
In the support apparatus, the support surface preferably comprises a convex surface formed by a stack of several columns.
In the support apparatus, at least one of the pair of holding portions preferably includes an elastic member and deforms due to a force inflicted by the sample.
In the support apparatus, preferably, at least one of the holding portions has a support portion partially consisting of an elastic material, and the sample is held by the support portion.
In the support apparatus, at least one of the holding portions preferably has an elastic member at a portion which can contact the sample.
In the support apparatus, at least one of the holding portions preferably has an annular support portion consisting of an elastic member.
In the support apparatus, at least one of the holding portions preferably has a support portion coupled to a main body via an elastic member.
The support apparatus preferably further comprises a rotary mechanism for rotating the holding portion about a shaft perpendicular to a surface of the sample.
The support apparatus preferably further comprises an adjustment mechanism for adjusting an interval between the pair of holding portions.
In the support apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism presses the sample to adjust the interval between the pair of holding portions.
In the support apparatus, preferably, in separating the sample by the fluid, the adjustment mechanism maintains a substantially constant interval between the pair of holding portions.
In the support apparatus, each of the pair of holding portions preferably has a chuck mechanism for vacuum-chucking the sample.
The support apparatus is suitable as a support apparatus for supporting a substrate having a porous layer as the fragile layer during separation processing.
According to the present invention, there is also provided a sample separating method characterized by comprising separating a sample having a fragile layer using the above separating apparatus.
In the separating method, water is preferably used as the fluid to be ejected from the jet unit.
According to the present invention, there is also provided a separating method of separating a substrate at a porous layer, the substrate being formed by bonding a non-porous layer side of a first substrate, in which the porous layer and the non-porous layer are sequentially formed on one surface, to a second substrate, characterized in that the above separating apparatus is used for separation.
According to the present invention, there is also provided a substrate manufacturing method characterized by comprising the step of bonding a non-porous layer side of a first substrate, in which a porous layer and the non-porous layer are sequentially formed on one surface, to a second substrate, and separating the bonded substrates at the porous layer, wherein the above separating apparatus is used in the separation step.
The present invention has been made in consideration of the above situation, and has as its object to provide a separating apparatus and method suitable to separate a plate-like sample represented by a substrate such as a bonded substrate stack, and a substrate manufacturing method to which the apparatus or method is applied.
According to the present invention, there is provided a separating apparatus for separating a plate-like sample, characterized by comprising a jet unit for ejecting a fluid for separating the sample to the sample, and first and second holding portions for sandwiching and holding the sample, wherein the first and second holding portions have holding surfaces with different shapes.
In the separating apparatus, preferably, the first holding portion holds one surface of the sample to make a deflection amount of the one surface due to a pressure of the fluid injected into the sample relatively small, and the second holding portion holds the other surface of the sample to make a deflection amount of the other surface due to the pressure of the fluid relatively large.
In the separating apparatus, preferably, the first holding portion holds one surface of the sample not to cause the one surface to deflect due to a pressure of the fluid injected into the sample, and the second holding portion holds the other surface of the sample to cause the other surface to deflect due to the pressure of the fluid.
In the separating apparatus, the holding surface of the first holding portion and the holding surface of the second holding portion preferably have different areas.
In the separating apparatus, preferably, the first holding portion has a holding surface for wholly holding one surface of the sample, and the second holding portion has a holding surface for partially holding the other surface of the sample.
In the separating apparatus, the holding surface of the first holding portion preferably comprises a flat surface.
In the separating apparatus, the holding surface of the first holding portion preferably comprises a curved surface.
In the separating apparatus, the holding surface of the second holding portion is preferably annular.
In the separating apparatus, preferably, the second holding portion has a plurality of projecting members, and the sample is held by tips of the plurality of projecting members.
In the separating apparatus, the second holding portion preferably has a shape allowing the sample to deflect while expanding at a central portion on a side of the second holding portion due to the pressure of the fluid injected into the sample.
In the separating apparatus, the second holding portion preferably has a shape allowing the sample to deflect and corrugate on a side of the second holding portion due to the pressure of the fluid injected into the sample.
The separating apparatus preferably further comprises a rotary mechanism for rotating at least one of the first and second holding portions about a shaft perpendicular to the holding surface to rotate the sample.
In the separating apparatus, preferably, the sample to be processed comprises a substrate formed by bonding first and second substrates, and the first and second substrates have different strengths.
According to the present invention, there is also provided a separating method of separating a plate-like sample, characterized by comprising holding the sample by sandwiching the sample by a pair of holding portions having holding surfaces with different shapes, and ejecting a fluid to a predetermined position in a direction of thickness of the sample, thereby separating the sample.
In the separating method, preferably, the sample to be separated has an internal fragile layer, and in separating the sample, the fluid is ejected to the fragile layer.
According to the present invention, there is also provided a separating method of separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising the separation step of ejecting a fluid to the fragile layer of the sample to separate the sample, wherein in the separation step, one surface of the sample is held to make a deflection amount due to a pressure of the fluid injected into the sample relatively small and the other surface of the sample is held to make a deflection amount due to the pressure of the fluid injected into the sample relatively large.
According to the present invention, there is also provided a separating method of separating a plate-like sample having an internal fragile layer at the fragile layer, characterized by comprising the separation step of ejecting a fluid to the fragile layer of the sample to separate the sample, wherein in the separation step, one surface of the sample is held to limit deflection due to a pressure of the fluid injected into the sample and the other surface of the sample is held to allow deflection due to the pressure of the fluid injected into the sample.
The separating method preferably further comprises rotating the sample about a shaft perpendicular to a major surface of the sample in separating the sample by the fluid.
In the separating method, preferably, the sample to be processed comprises a sample formed by bonding first and second substrates, and the first and second substrates have different strengths.
According to the present invention, there is also provided a separating method of separating a composite substrate which has a fragile layer between a first substrate having a relatively low strength and a second substrate having a relatively high strength, at the fragile layer, characterized by comprising the separation step of ejecting a fluid to the fragile layer to separate the composite substrate, wherein in the separation step, the first substrate is held to make a deflection amount due to a pressure of the fluid injected into the composite substrate relatively small and the second substrate is held to make a deflection amount due to the pressure of the fluid injected into the composite substrate relatively large.
According to the present invention, there is also provided a separating method of separating a composite substrate which has a fragile layer between a first substrate having a relatively low strength and a second substrate having a relatively high strength, at the fragile layer, characterized by comprising the separation step of ejecting a fluid to the fragile layer to separate the composite substrate, wherein in the separation step, the first substrate is held to limit deflection due to a pressure of the fluid injected into the composite substrate and the second substrate is held to allow deflection due to the pressure of the fluid injected into the composite substrate.
According to the present invention, there is also provided a substrate manufacturing method characterized by comprising the step of bonding a non-porous layer side of a first substrate, in which a porous layer and the non-porous layer are sequentially formed on one surface, to a second substrate, and separating the bonded substrates at the porous layer, wherein any one of the above separating apparatuses is used in the separation step.
According to the present invention, there is also provided a substrate manufacturing method characterized by comprising bonding a non-porous layer side of a first substrate, in which a porous layer and the non-porous layer are sequentially formed on one surface, to a second substrate, and separating the bonded substrates at the porous layer, wherein the separation step is executed using any one of the above methods.
According to the present invention, there is also provided a holding apparatus for holding a sample in ejecting a fluid to a predetermined position in a direction of thickness of the sample to separate the sample, characterized in that the sample is held by a pair of holding portions whose holding surfaces for holding the sample have different shapes.
Further objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings.